Noun watchdog has 2 senses
  1. watchdog - a guardian or defender against theft or illegal practices or waste; "she is the global watchdog for human rights abuses"
    --1 is a kind of
    defender, guardian, protector, shielder
  2. watchdog, guard dog - a dog trained to guard property
    --2 is a kind of working dog
    --2 has particulars: kuvasz; attack dog; housedog; schipperke; pinscher